INTRODUCTION: High weight and high percent mammographic breast density are both breast cancer risk factors, but are negatively correlated. Therefore we wanted to obtain more insight in this apparent paradox. METHODS: We investigated in a longitudinal study how weight change over menopause is related to changes in mammographic breast features. 591 participants of the EPIC-NL cohort, were divided into 3 groups according their prospectively measured weight change over menopause: 1) weight loss (> -3.0 %), 2) stable weight (between -3.0 % and +3.0 %) and 3) weight gain (>3.0 %). SPSS GLM univariate analysis was used to determine both the mean breast measure changes in, and the trend over the weight change groups. RESULTS: Over a median period of 5 years, the mean change in percentage density in these groups was -5.0 % (95 % CI: -8.0; -2.1), -6.8 % (95 % CI: -9.0; -4.5) and -10.2 % (95 % CI: -12.5; -7.9), respectively (p-trend = 0.001). The mean change in dense area was -16.7 cm(2) (95 % CI: -20.1; -13.4), -16.4 cm(2) (95 % CI: -18.9; -13.9) and -18.1 cm(2) (95 % CI: -20.6; -15.5), respectively (p-trend = 0.437). Finally, the mean change in nondense area was -6.1 cm(2) (95 % CI: -11.9; -0.4), -0.6 cm(2) (95 % CI: -4.9; 3.8) and 5.3 cm(2) (95 % CI: 0.9; 9.8), respectively (p-trend < 0.001). CONCLUSIONS: Going through menopause is associated with a decrease in both percent density and dense area. The decrease in percent density is largest in women who gain weight, due to an increase in the nondense tissue. The decrease in dense area is not related to weight change. So the fact that both high percent density and high weight or weight gain are associated with high postmenopausal breast cancer risk, can probably not be explained by an increase (or slower decrease) of dense area in women gaining weight compared to women losing weight or staying stable weight. These results suggest that weight and dense area are presumably two independent postmenopausal breast cancer risk factors.
Mendeley saves you time finding and organizing research
Choose a citation style from the tabs below